The assassination of top Hamas leader Ahmed Jabari is a declaration of war, Fawzi Barhoum, a spokesman for the Islamist movement, said Wednesday.

Barhoum’s statement came as Hamas’s armed wing, Izz ad-Din al-Qassam Brigades, vowed to avenge the killing of its commander.

Palestinian Authority President Mahmoud Abbas condemned the Israeli military operation and called for saving the residents of the Gaza Strip from war. He also called for an emergency meeting of the Arab League to discuss the Israeli “aggression” against the Gaza Strip.

Chief PLO negotiator Saeb Erekat said that the PA holds Israel responsible for the “brutal aggression” against the Gaza Strip. “The occupation has committed a grave crime and crossed all red lines,” Barhoum, the Hamas spokesman, said.

“This is a real declaration of war. The enemy will pay a heavy price for its crime and will regret the moment it thought of perpetrating it.”